1. Field of the Invention
The present disclosure relates to a headrest apparatus moveable back and forth in cooperation with a seat back, and more particularly, to a headrest apparatus moveable back and forth in cooperation with a seat back, in which a headrest assembly including a headrest main body, a headrest frame, and a headrest guide remains in a suitably protruded position in an upright position of the back seat to meet safety regulations on height of the headrest, and is configured to be retreated to a rest position in conjunction with movement of the seat back during folding operation of the seat back, thereby providing convenient folding operation of the backseat.
2. Description of Related Art
Generally, a seat for an automobile includes a seat cushion supporting the hips, a seat back supporting the back of the passenger, and a headrest supporting a neck and a head of an occupant.
The seat back provides supporting force to the back and waist portions for a passenger's comfort. The headrest supports a passenger's neck and head to provide comfort to the neck, and in the event of a rear-end collision, suitably protects the passenger's head and neck by preventing abrupt movement of the head backward.
Recently, in order to maximally utilize vehicle space, folding seats that can be of various structures that allow a seat to be folded to easily carry a large freight are provided. That is, unoccupied seats are tilted forward into a flat position, thereby providing sufficient luggage compartment and flat loading surface.
For example, FIG. 1 illustrates a floor-embeddable seat, which comprises a seat back 2, and a height adjustable head rest 3 that is embeddable into the seat back. The floor-embeddable seat is capable of being kept in a receiving space 1 formed in a floor of a vehicle. Depicted in the accompanying FIG. 2 is a fold-and-dive seat, which is configured to collapse upon folding a seat back 2.
Regarding a general folding seat, North American countries have Regulations on the height of a seat back, which set limitations on the minimum height of the seat back. By lengthening the height of a seat back or a headrest in order to meet those Regulations, the lengthened seat back or headrest may interfere with or protrude into the interior of the vehicle, and may make the folding operation itself impossible.
According to current seat back and headrest related Regulations, the height of an upper end of the headrest should be at least 750 mm. An exception to this Regulation is shown in exemplary FIG. 3. FIG. 3 exemplifies a case where a front projection height S of a headrest 3 from the front side of a seat back 2 exceeds 40 mm, and the Regulations are suitably loosened. Accordingly, if a height (HLE) between a hip (H)-point of a seat cushion and a lower end of the headrest 3 exceeds 460 mm, it is deemed that the regulation is satisfied (new regulation FMVSS (Federal Motor Vehicle Safety Standards) 202a).
With a shorter seat back, the folding operation of the seat back becomes convenient. However, since the front projection height S of the headrest should be at least the regulated value, the front side of the headrest may interfere with the seat cushion when the seat back is tilted in a flat position. Accordingly, the seat back may not be able to be fully tilted to the seat cushion.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.